The long-standing traditional view, once widely accepted,[by whom?] is that the Celtic language, Ogham script and culture were brought to Ireland by waves of invading or migrating Celts from mainland Europe. This theory draws on the Lebor Gabála Érenn, a medieval Christian pseudo-history of Ireland along with the presence of Celtic culture, language and artefacts found in Ireland such as Celtic bronze spears, shields, torcs and other finely crafted Celtic associated possessions. The theory holds that there were four separate Celtic invasions of Ireland. The Priteni were said to be the first, followed by the Belgae from northern Gaul and Britain. Later, Laighin tribes from Armorica (present-day Brittany) were said to have invaded Ireland and Britain more or less simultaneously. Lastly, the Milesians (Gaels) were said to have reached Ireland from either northern Iberia or southern Gaul. It was claimed that a second wave named the Euerni, belonging to the Belgae people of northern Gaul, began arriving about the sixth century BC.
They were said to have given their name to the island.
A more recent theory, with broad support among archaeologists, is that Celtic culture and language arrived in Ireland as a result of cultural diffusion. This theory proposes that the Celticisation of Ireland may have been the culmination of a long process of social and economic interaction between Ireland, Britain and adjacent parts of Continental Europe.